Tips on How to Clean a Gas Furnace- A Helpful Step-by Step Guide to Cleaning Your Gas Furnace

by | Jan 27, 2025 | HVAC, Furnace Repair

SUMMARY

When it comes to maintaining the efficiency, safety, and lifespan of your gas furnace, one of the best things you can do is to clean it. Not only is it essential to clean a gas furnace (roughly once a year), but it also reduces serious safety hazards for your household, like carbon monoxide leaks. So, in this helpful article, we’ll provide some useful advice on how to clean a gas furnace.

Preparing to Clean Your Gas Furnace

Before you begin cleaning your gas furnace, there are several things you should do to prepare for the cleaning process. First, you should take safety precautions. Before starting work, you should turn off the circuit breaker, close the main gas valve, and ensure the furnace is completely cool. This makes sure that you won’t hurt yourself or the furnace won’t turn on while you’re cleaning it. You should also wear safety gear to protect yourself from dust and debris from cleaning the furnace. Make sure your work area is clear and has good ventilation, as well as prepping with the tools you need to clean the furnace. For example, screwdrivers, ratchets, a soft-bristled brush, and a microfiber cloth are essential tools and equipment to clean your gas furnace.
Two men inspecting floor plans with a gas furnace in the background.

Cleaning Your Gas Furnace

Now that you have shut down your furnace, gathered your tools, and have a safe workspace, you can start getting to cleaning your gas furnace. The first thing you will want to do is to use a damp microfiber rag to wipe down the exterior of the furnace. This will remove any dust and grime. The next thing you will want to do is to carefully remove the furnace access door by pulling it out. It might have a burner cover, so you will have to use a screwdriver. Now that you have opened the furnace and have access to its inside, you can use a shop vacuum to clean the burners and base of the furnace. You could also lift the blower door and vacuum there as well. Then, after you have vacuumed, this is where your wire brush will come in handy. You can remove the burners and use a wire brush to scrub them free of any carbon deposits. Then, you can clean the flame sensor with fine steel wool to remove any carbon buildup there. Lastly, you can vacuum any dust or debris from inside the combustion chamber. Your cleaning is complete! We will move on to the final step: furnace reassembly and testing. You’re nearly finished with the process.
A gas furnace installed in a wooden house framework.

Gas Furnace Reassembly & Testing

After you have cleaned your gas furnace, the next big phase is reassembling it, which involves several important steps. If you follow these steps, your gas furnace will continue to operate safely and successfully. First, you must carefully reattach the access panel to the combustion chamber. Make sure all the screws are securely fasted to prevent air leaks. Next, you can reconnect any electrical wires that might’ve been disconnected during cleaning. You can also restore the gas supply by slowly opening the gas valve to prevent damage. Lastly, if you replace your filthy gas furnace filter with a new one, ensure it is correctly positioned in its compartment. Now that you have reassembled your furnace, you can test it to see if it is in working order. You can inspect if the vent pipes are all properly connected. Properly connected vent pipes prevent dangerous gases like carbon monoxide from leaking into your home. You can restore the power by switching on the circuit breaker. Next, you can adjust the thermostat back to the temperature it was, which would be higher than the current room temperature. Perform basic performance checks for the burner flames, check to see if warm air is coming out of your home vents, and listen closely to see if there aren’t any unusual noises coming from your furnace. Great job! You have completed your furnace cleanup and won’t have to worry about it until next year!
A man inspecting a gas furnace.

Conclusion

Besides the basic process that we outlined on how to clean a gas furnace, hiring a professional gas furnace technician is also recommended. They will be able to inspect your furnace, clean it, and replace any damaged or worn-down parts. This is especially the case if your gas furnace is not heating up as easily, making loud noises, and not heating some rooms in your house as well as others. So, it is good to schedule regular professional inspections so you can have a more thorough maintenance and cleaning process that will maintain the health of your gas furnace. That’s why we at Seattle Heating and Cooling offer our services to help you. With our expert guidance and cutting-edge solutions, we can make sure your furnace is in tip-top shape by offering our professional furnace repair and inspection services. You can call us at 206-600-5800 or contact us to book an appointment with us today quickly.

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